In general, various semiconductor devices such as resistors, transistors, and diodes are formed on or within a semiconductor substrate. These semiconductor devices are formed by patterned conductor layers and dielectric layers. Trench isolations are used to separate and isolate active regions of the semiconductor devices from each other on the semiconductor substrate. However, when a trench isolation is formed adjacent to a source region or a drain region of the active region, a facet surface is often caused in the source region or drain region, and the facet surface raises processing issues subsequently, for example, when a contact is landed on the source region or drain region.